ON THE ROAD; GRAVEL, CLAY, AND LIMESTONE PAVING THE WAY

Today's roads and highways connecting farm to market, suburban to urban, and the vast interstate system are a product of geological resources that grew from dusty dirt roads to corded wood roads to hard surfaces. Clays for bricks provided hard surfaces to move goods across town while gravel roads improved the farm to market system to transfer produce from the farm to the cities. Brick and gravel gave way to crushed limestone and concrete, later followed by asphalt as an alternative to concrete roads. Mom and Pop operations gave way to small mining operations that in turn became larger mining operations providing the nation with mining products to enhance transportation. In Iowa alone, nearly 30 million tons of limestone were mined and crushed for use in roads and highways. In this presentation we will trace the history and geology of the use of aggregates for our roadways and highways that serve as the connecting link with all phases of society.